ort8850 Lattice Semiconductor Corp., ort8850 Datasheet - Page 101

• Manufacturer Part Number: ort8850
• Description: Field-programmable System Chip Fpsc Eight-channel X 850 Mbits/s Backplane Transceiver
• Manufacturer: Lattice Semiconductor Corp.

Lattice Semiconductor
FPSC Maximum Junction Temperature
Once the power dissipated by the FPSC has been determined, the maximum junction temperature of the FPSC
can be found. This is needed to determine if speed derating of the device from the 85 °C junction temperature used
in all of the delay tables is needed. Using the maximum ambient temperature, T
the device, Q (expressed in °C), the maximum junction temperature is approximated by:
T
Table 37 lists the thermal characteristics for the package used with the ORCA ORT8850 Series of FPSCs.
Package Thermal Characteristics
Table 37. ORCA ORT8850 Plastic Package Thermal Guidelines
Heat Sink Information
The estimated worst-case power requirements for the ORT8850 are in the 4 W to 5 W range. Consequently, for
most applications an external heat sink will be required. The following table lists, in alphabetical order, heat sink
vendors who advertise heat sinks aimed at the BGA market.
Table 38. Heat Sink Vendors
Package Coplanarity
The coplanarity limits of the Lattice packages are as follows:
• PBGAM: 8.0 mils
680-Pin PBGAM*
* The 680-Pin PBGAM package includes 2 oz. copper plates.
Jmax =
T
Aavid Thermalloy
Chip Coolers (Tyco Electronics)
IERC (CTS Corp.)
R-Theta
Sanyo Denki
Wakefield Thermal Solutions
Amax
Package
+ (Q • θ
JA
)
Vendor
0 fpm
13.4
Θ Θ Θ Θ
200 fpm
JA (°C/W)
Concord, NH
Harrisburg, PA
Burbank, CA
Buffalo, NY
Torrance, CA
Pelham, NH
11.5
101
Location
500 fpm
10.5
[phone]
[phone]
[phone]
[phone]
[phone]
[phone]
T = 70 °C Max, T
ORCA ORT8850 Data Sheet
Amax
Maximum Power (W)
, and the power dissipated by
Phone
J
4.10
= 125 °C Max, 0 fpm